This weekend I jumped on the interstate that went though our mountains. Looking at my SGII, My water temp was 215 and my EOT was 228. It as 92deg out, and I was climbing elevation. I had cruise set at 70mph, and I have the SRL tune. Is my engine running hotter than it should? I know i'm within the 15 deg delta, but aproaching 230 deg for oil temp and 215 for water just seems high especially when the thermostat is 190 deg. A few things to note

-Coolant filter installed about 10k miles ago along with coolant flush
-EGR and Oil coolers replaced about 2k miles ago
-I couldnt tell if the fan was turning on, but I plan to program it into the SGII to monitor from here on out. It didnt sound like the fan came on, but at highway speeds i'm not sure if I'd hear it.

THanks in advance

 

A little high I think but nothing to worry about yet. I towed yesterday on some pretty good hills 91* outside temp. Saw similar numbers but my oil temp was a bit lower. You would know if the fan kicked into high gear, it's pretty hard to miss. Get that SG set up and watch the fan. Is the EGR valve plugged in?

Fan Speed Sensor (RPM)

TXD: 07E022099F

RXF: 04620509069F

RXD: 3010

MTH: 000100040000

NAM: FSS

 

Thanks for giving the info for Fan Speed SGII. I'll program it in today. I wasnt towing anything either, so i would have thought it should have been lower temps than yours. The EGR Valve is plugged in, but i'm not sure if the SRL Tune disables EGR or not. I do remember hearing the fan while driving in the city, but that was last summer. I havent really heard it this year. Would I be able to hear it at highway speeds?

Joe

 

From the Tech folder:

Recommended readings - Temperatures and Pressures

STOCK READINGS
Normal Severe Service Alarm
Tranny Temp 150 - 195 195 - 200 220
Coolant Temp 190 - 200 200 - 215 215+
Fuel Press 60 - 50 50 - 45 45
EGT - pre Turbo 650 - 1200 1200 - 1250 1300
EGT - post Turbo 700 900 1000
Boost 0 - 26 27 - 28 28
Oil Temp 200 - 215 215 - 230 230+


READINGS WITH TUNERS
Normal Severe Service Alarm
Tranny Temp 150 - 195 195 - 220 230
Coolant Temp 190 - 215 215 - 220 220+
Fuel Press 60 - 50 50 - 45 45
EGT - pre Turbo 650 - 1200 1200 - 1300 1300
EGT - post Turbo 700 900 1000
Boost 0 - 26 27 - 30 30+
Oil Temp 200 - 230 230 - 235 235+
__________________
Thanks Mark

Some say fan kicks on at 210, some say 215, others say 220. Full explanation: Engine temperature is not the only parameter that the PCM monitors to determine cooling fan operation. This is the reason that you will see some variation in engine temperature as it correlates to fan operation. The operation/description of the FSS (Fan Speed Sensor) from the PC/ED manual has a fairly good explanation as to how the system "thinks". This is not your traditional engine hits temp X and the fan clutch locks up. The fan speed sensor is a Hall-Effect sensor integral to the vistronic drive fan (VDF). The powertrain control module (PCM) will monitor sensor inputs and control the VDF speed based upon engine coolant temperature (ECT), transmission fluid temperature (TFT) and intake air temperature (IAT) requirements. When an increase in fan speed for vehicle cooling is requested, the PCM will monitor the FSS signal and output the required pulse width modulated (PWM) signal to a fluid port valve within the VDF. Engine begins to defuel at 221 deg. The thermostat begins to open at about 190*F to 195*F and is not fully open until about 215*F to 219*F..

 

So I'm definatley in the normal range, but on the very high end. Considering I wasnt towing anything, I dont like the numbers that high. If my fan is not kicking in, I'm guessing its most likely the fan clutch that would be the issue right?

 

Oh yes, you would have to be CRANKING the radio to not hear it when it goes 2k+ RPM 's.

Pulling hills is pretty hard work given the weight of the truck. I suspect that contributes significantly to higher temps, especially if they are long and steep.

 

(You type fast! )Possibly. But the fan clutch is good about throwing a code if something's wrong. Many possible causes. Thermostat, water pump, cavitation in front cover. Rich fuel mixture, EGR valve etc.

It may be fine depending on how hard the truck was working and for how long. As you noticed the numbers you're seeing are in spec.

 

thanks for all the info, its much appreciated. i guess the key word you speak are that the temps are still in spec. maybe i better wait before i start chasing an issue that might not be there. ill monitor temps, watch fan speeds, and take it from there. thanks!

 

Forgot to mention cleaning the cooler "stack". The radiator, Charge Air Cooler, and A/C condenser can collect a lot of hard to see grass bugs and dirt and make you run a bit warmer also.

Different software flash versions in the truck's PCM may make it act differently but my truck spools the fan up 2k rpm or so at 215 degrees and if it makes it to 217 it will go to 3 or 3.5k rpm. Cold is around 400 rpm and at normal operating temps it Hangs around 600 rpm or so. It kinda wanders around by few rpm and doesn't keep the exact same speed more than a couple of seconds at a time.